Meandering rivers on Earth are iconic landforms often associated to presence of vegetation. The occurrence of a few spectacular meandering rivers on planet Mars raises the question what the precise mechanisms are that lead to river meandering, and what the role is of biogeomorphic feedbacks. These will briefly be reviewed from field data, experiments, theory and numerical modelling, and from statistical causation as well as mechanistic causation. I will show that the current interest in the role of rooting in outer bank erosion is a bias, and inner-bend protection by above-ground biomass and/or cohesive sediment is as important. This also sheds new light on meandering in the last 541 million years on this planet as inferred from the rock record. In turn, this leads to viable hypotheses for the Martian environment before, say, 3.8 billion years ago. However, the lack of braided rivers leads to a new conundrum. My research is about ‘living landscapes’: the rivers, coastal plains and deltas that form through interactions between physical processes and organisms, as well as the controls without organisms.
A short background movie about water-related landforms on Mars, for those unfamiliar with the big picture, is available here: http://fastfacts.nl/en/content/maarten-kleinhans-rivers-red-planet
